The parameters of methadone treatment may be systematically manipulated so as to determine their contributions to treatment outcome. This proposal will examine a variety of such behavioral and pharmacological parameters within the context of both methadone maintenance and methadone detoxification. The purpose of this project is three-fold. First, to evaluate contingency management procedures that could be utilized in the clinical management of methadone maintenance patients. Second, because many opiate abusers are unwilling to participate in a long-term methadone maintenance program, we propose to examine various parameters of ambulatory methadone detoxification, in order to determine if ambulatory detoxification can be a viable and efficacious treatment alternative. Finally, the technologies and knowledge-base resulting from this research will be rapidly disseminated on a local, regional, national, and international basis in order to further the battle against i.v. drug abuse and the spread of HIV infection. The specific contingency management procedures to be evaluated included reinforcing drug free urines with take-home privileges, reinforcing attending skills training classes with take-home privileges, and reinforcing meeting treatment plan objectives with take-home privileges. The dose and duration parameters of ambulatory methadone detoxification will be examined in clients who do not wish to participate in methadone maintenance treatment. The additional benefits of adding a contingency management program during ambulatory detoxification will, also, be evaluated. These studies will provide important information about the relative efficacy of contingency management procedures within the methadone treatment setting, and of the general utility and optimal parameters for ambulatory methadone detoxification. Included in the study designs will be multiple outcome measures so as to determine relative efficacy along different dimensions (e.g. drug use behaviors, employment status, psychiatric status, and global indices found in the Addiction Severity Index). An extended follow-up will also be included in the design of the detoxification protocols to ensure comprehensive information on subjects'post-treatment functioning. These data will provide for the evaluation of both the transient and the enduring benefits of treatment.